Many types of completions are used in sand control operations. Generally, a completion assembly is positioned in a wellbore and a service tool is used in cooperation with the completion assembly to create a gravel pack in the annulus around the completion assembly. The gravel pack helps filter out sand and other particulates from a desired production fluid entering the wellbore.
The gravel pack is formed by flowing a gravel slurry downhole to the well zone to be treated. At the well zone, a carrier fluid is separated from the gravel slurry leaving gravel to form the gravel pack. The carrier fluid reenters the completion assembly through a screen and is returned upwardly through a washpipe section of the service tool. The return flow is directed upwardly through a central passage of the washpipe and then diverted outwardly to an annular flow path through a crossover port.
In some applications, the service tool assembly is used to treat multiple zones in a single trip downhole. The service tool assembly is deployed into the wellbore while constrained within a completion assembly. As the completion assembly is anchored in the wellbore and the service tool assembly is moved to treat upper zones, the service tool assembly becomes exposed to the full casing diameter which is substantially larger than the outside diameter of the service tool assembly. When weight is applied from the surface onto the service tool assembly to maintain its position, severe buckling loads can be experienced at the service tool assembly. Additionally, buckling loads can occur during pumping operations while gravel packing one or more well zones.